Vocabulary : Radiotelegraphic to Radius vector

Radiotelegraphic : Of or pertaining to radiotelegraphy; employing, or used or employed in, radiotelegraphy.
Radiotelegraphy : Telegraphy using the radiant energy of electrical (Hertzian) waves; wireless telegraphy; -- the term adopted for use by the Radiotelegraphic Convention of 1912.
Radiotelephone : A wireless telephone.
Radiotherapy : Treatment of disease by means of Rontgen rays or other forms of radioactivity.
Radiothorium : A radioactive substance apparently formed as a product from thorium.

Radious : Consisting of rays, as light. ;; Radiating; radiant.
Radish : The pungent fleshy root of a well-known cruciferous plant (Raphanus sativus); also, the whole plant.
Radium : An intensely radioactive metallic element found (combined) in minute quantities in pitchblende, and various other uranium minerals. Symbol, Ra; atomic weight, 226.4. Radium was discovered by M. and Mme. Curie, of Paris, who in 1902 separated compounds of it by a tedious process from pitchblende. Its compounds color flames carmine and give a characteristic spectrum. It resembles barium chemically. Radium preparations are remarkable for maintaining themselves at a higher temperature than their surroundings, and for their radiations, which are of three kinds: alpha rays, beta rays, and gamma rays (see these terms). By reason of these rays they ionize gases, affect photographic plates, cause sores on the skin, and produce many other striking effects. Their degree of activity depends on the proportion of radium present, but not on its state of chemical combination or on external conditions.The radioactivity of radium is therefore an atomic property, and is explained as result from a disintegration of the atom. Thi
Radius : A right line drawn or extending from the center of a circle to the periphery; the semidiameter of a circle or sphere. ;; The preaxial bone of the forearm, or brachium, corresponding to the tibia of the hind limb. See Illust. of Artiodactyla. ;; A ray, or outer floret, of the capitulum of such plants as the sunflower and the daisy. See Ray, 2. ;; The barbs of a perfect feather. ;; Radiating organs, or color-markings, of the radiates. ;; The movable limb of a sextant or other angular instrument.
Radius vector : A straight line (or the length of such line) connecting any point, as of a curve, with a fixed point, or pole, round which the straight line turns, and to which it serves to refer the successive points of a curve, in a system of polar coordinates. See Coordinate, n. ;; An ideal straight line joining the center of an attracting body with that of a body describing an orbit around it, as a line joining the sun and a planet or comet, or a planet and its satellite.